How many mole Fe2+ ions are formed, when excess of iron is treated with 50ml of 4.0M HCl under inert atmosphere? Assume no change in volume.

Fe+2HCl→FeCl2+H22 moles of HCl form one mole of Fe2+ Given number of moles of HCl= Molarity × Volume of solution in litre=4×50×10-3=0.2 Number of moles of Fe2+=12 moles of HCl (from equation)  So amount of Fe2+ formed is 0.1 mole